This application is a 371 of PCT/JP08/05160 filed Nov. 16, 1998.
The present invention concerns a modeling composition suitable for preparing modeling material for modeling rows of teeth for dental treatment or for manufacture of mouthpieces for protection of the oral cavity during rugby, boxing, or other sports activity, for modeling the external ear for the manufacture of compact, order-made hearing aids to be inserted in the external auditory canal, for modeling a foot for manufacturing order-made shoes, for modeling the digits of a hand, foot, etc., for manufacture of silicon rubber replicates, etc., for compensating for the loss of such body parts, for the manufacture of replicas of humans, animals, and other natural objects and articles, etc., for model-making and other hobbies, and for molding of automobile parts, etc. The present invention also concerns a method of preparing a modeling material using the abovementioned modeling composition, a modeling material obtained by the modeling material preparation method, and a modeling method using the abovementioned modeling material.
In recent years, various modeling materials have been developed, for example, for dental treatment, manufacture of protective equipment, and the modeling of parts for hobby or industrial use. For example, synthetic resins, such as polysiloxane rubbers, polysulfide rubbers, polyether rubbers, and silicone resins, and natural high polymers, such as agar and alginic acid, are used as modeling material for obtaining the impression of a row of teeth.
However, synthetic resins are cold-set by a chemical reaction, and though being easy to use, are high in cost, and in cases of use inside an oral cavity, there is a danger of clogging the bronchus since the fluidity is high. Also, when such a synthetic resin is imbibed erroneously, it may have an adverse effect on the human body since it cannot be digested.
Among natural high polymer modeling materials, those having agar as the main component are thermoplastic materials. These thus accompany difficult control of temperature during handling and thus a danger of burns, etc. With modeling materials having alginic acid as the main component, large amounts of water are contained in the structural gaps of the hardened gel and since this water is released after setting, large changes occur with time and the dimensional precision is low.
Various natural high polymer modeling materials that can take the place of alginic acid and agar have thus been examined recently. Among such materials, konnyaku has been used as a food from old and since it has been confirmed to be extremely high in safety, the use of konnyaku as a modeling material is being examined.
For example, Japanese Laid-open Patent Publication No. Sho 60-19471 discloses a modeling material, which uses glucomannan and with which glucomannan and water are heated to 90xc2x0 C. or more upon addition of a basic catalyst and then used for modeling, etc. However, since this modeling material requires a high temperature process, it was difficult to use on a human body.
As a glucomannan that can be set at room temperature, Japanese Laid-open Patent Publication No. Hei 5-194603 discloses a transparent glucomannan gel, which is comprised of glucomannan, a tetravalent borate, and water, and has a water content of 95 weight % to 99.5 weight %. However, since the water content is high, the gel has a low hardness even after setting and thus cannot be used as modeling material. Also, since approximately 3 hours is needed for setting, the gel was difficult to apply to the oral cavity and various other portions of the human body.
Upon careful examination towards solving the above problems, the present applicant has come to complete a cold-set modeling material comprised of glucomannan, which is set with a basic curing agent, water, a thickening agent, and a modifier, and has applied for a patent for this art by way of Japanese Patent Application No. Hei 8-227756.
However, the above prior-art modeling material that uses glucomannan was found to have the following problems.
(1) Since a basic curing agent is added afterwards, the mixing tended to be inadequate and uneven setting tended to occur.
(2) When the water content was reduced in order to make the elastic deformation factor and permanent deformation factor of the hardened gel small, the hydration of glucomannan tended to be non-uniform and the obtaining of an adequate strength became difficult.
(3) Since a basic curing agent is added to set the glucomannan, and the pH thus rises to nearly 11, there was a problem of irritation of the mucous membrane in cases of use inside an oral cavity. The excessively high pH also made use difficult as modeling material for the modeling of the digits of a hand or foot upon fracture or loss of a hand or foot, modeling for hobby goods, and other modeling purposes.
(4) Though the modeling material of alginate, etc., was kneaded upon being placed in a rubber ball in the process of modeling, the making of the gel uniform was difficult and expertise was required for the procedure. Furthermore, the prior-art modeling material had a strong adhesive force, and for example in the process of obtaining a teeth row impression, considerable labor and time were required in removing the modeling material from the teeth row of a patient and the patient was thus subjected to extreme stress and pain.
(5) Since the modeling material was too hard, patients were subjected to extreme pain in the process of modeling an external ear or ear cavity.
(6) Though plaster was normally used for the modeling of a hand or foot or the modeling of a natural object, the workability was inadequate in that the object became soiled in the process of modeling and peeling of the modeling material was difficult.
The present invention has been made to solve the above problems of the prior art and objects thereof are to provide a modeling composition, which sets at room temperature just by the addition of a prescribed amount of water, is excellent in elasticity, has a high gel strength, is excellent in terms of safety, and with which a modeling material can be formed readily at low cost, to provide a modeling material preparation method, with which a modeling material, that has a uniform surface and can accurately replicate the original, can be obtained readily, to provide a modeling material, which has plasticity in the process of modeling, loses the plasticity and changes to an elastic body in the process of removal from a subject after modeling, enables a mold that accurately maintains the three-dimensional and complex form of the original to be obtained, is low in the elastic deformation factor and permanent deformation factor after setting, enables arbitrary adjustment of the pH of the water that percolates out of the gel within a pH range of 7 to 12 without sacrificing the precision of modeling, and thus, for example, enables adjustment of the pH to 8.6 or less to lower the irritability to the oral cavity mucous membrane and provide excellent safety in the obtaining of a teeth impression and yet also enables the pH to be set higher to further increase the precision after setting in applications besides human body applications, and to provide a modeling method with which modeling can be performed by simple handling and in a short time and thus with the burden on a user or subject being alleviated.
In order to solve the above-described problems of the prior art, the present invention provides a modeling composition containing 100 weight parts of glucomannan, 1 to 100 weight parts or more preferably 2 to 75 weight parts of a basic curing agent, 9 to 500 weight parts or more preferably 50 to 250 weight parts of a neutral solute, 0 to 30 weight parts or more preferably 1 to 20 weight parts of a tempering agent, and 0 to 300 or more preferably 1 to 150 weight parts of a modifier.
The following excellent effects can be realized with the above arrangement.
a. A modeling material, which sets to an elastic body at room temperature simply by the addition of a prescribed amount of water, has a high gel strength, is excellent in safety, and can be molded readily at low cost, can be obtained.
b. Since prescribed amounts of basic curing agent and modifier are contained, the glucomannan content per unit amount of gel can be made higher than in the prior arts.
c. Generally, when the glucomannan content per unit amount of gel increases, the gelling rate becomes too fast, making modeling difficult and leading to significant loss in ease of handling. However, with the present invention, the setting time can be adjusted freely simply by changing the content of the neutral solute. That is, it has found that the amount of water taken in by glucomannan can be restrained by making a hydrophilic neutral solute coexist in the aqueous gelling solution. As a result, it has become possible to increase the amount of glucomannan per unit amount of gel and control the gelling rate, in other words, the rate of intake of water into glucomannan at the same time. Also, since the amount of glucomannan per unit amount of gel can be increased, the toughness of the resulting gel can be increased significantly.
d. Since modeling material can be formed simply by shaking, unlike prior arts with which the modeling material is formed by kneading the modeling composition with a spatula, the modeling material can be made extremely readily even by an unskilled person.
e. Since the modeling composition is elastic and can be peeled off readily, the workability of the modeling work can be improved considerably and the modeling yield can be improved significantly.
In the modeling material preparation method of the present invention, 100 weight parts of glucomannan, 1 to 100 weight parts or more preferably 2 to 75 weight parts of a basic curing agent, 9 to 500 weight parts or more preferably 50 to 250 weight parts of a neutral solute, 0 to 30 weight parts or more preferably 1 to 20 weight parts of a tempering agent, and 0 to 300 or more preferably 1 to 150 weight parts of a modifier are mixed with an amount of water which is 300 to 3600 weight parts or more preferably 300 to 1200 weight parts per 100 weight parts of the abovementioned glucomannan and at the same time with which the concentration of the abovementioned neutral solute will be from 3 weight % to saturated with respect to the water.
The following excellent effects can be realized by the above arrangement.
a. A modeling material, which has a uniform surface and can accurately replicate the original, can be obtained.
b. Since the modeling material has elasticity, it is excellent in peelability in the process of mold release after modeling and can be peeled off readily in a short time.
c. Since it has become possible to increase the amount of glucomannan per unit amount of gel, the toughness of the resulting gel can be increased considerably and elasticity and other forms of mechanical strength can be increased.
The modeling material of the present invention is comprised of a modeling material prepared by the above-described modeling material preparation method.
With this arrangement, modeling material, which enables high modeling precision due to the low elastic deformation factor and permanent deformation factor after setting and with which the irritability to skin, the mucous membrane inside an oral cavity, etc., can be lowered, can be obtained.
Furthermore, the modeling material of the present invention has plasticity in the process of modeling, loses the plasticity and changes to an elastic body in the process of removal from a subject after modeling, enables the obtaining of a mold that accurately maintains the three-dimensional and complex form of the original, is low in the elastic deformation factor and permanent deformation factor after setting, enables the pH of the water that percolates out of the modeling material or mold to be adjusted to a predetermined pH within a pH range of 7 to 8.6, etc., is excellent in safety, enables modeling of high precision, and can lower the irritability to skin, the mucous membrane inside an oral cavity, etc. Since the modeling material can be formed simply by shaking, the modeling material can be made extremely readily even by an unskilled person. Since the modeling material has elasticity and can be peeled off readily, the workability of the modeling work can be improved considerably and the modeling yield can be improved significantly.
The modeling method of the present invention is comprised of a pressing process in which the abovementioned modeling material is pressed against the subject to be modeled, and a setting process, in which the modeling material that has been pressed in the abovementioned pressing process is set.
By the above arrangement, since a mold can be acquired with simple handling and in a short time, the burden placed on a subject can be alleviated. Furthermore, since the modeling material has elasticity, the peelability in the process of mold release after modeling is excellent and the peeling can be performed readily in a short time.